4 quarts does not equal 1 gallon milk jug?

[beertastic]

I'm just starting doing all grain batches and using BeerSmith, so I'm trying to get a little more serious about my volumes.

I thought it would be a good idea to mark the side of a gallon jug by the quart, but I came up really short. I measured 2 cups (1/2 qt) at a time, and let everything settle before marking and measuring.

Are the 1 gallon jugs really that much more than 1 gallon? Or am I measurically challenged

What are you guys using to measure out quarts/gallons with decent accuracy?

 

[Dan]

I used a 2 qt picture to measure out gallon marks on my keggle and a glass measuring cup to find out where the actual 2 qt mark came up to on that picture. (do you think you could shrink your image a bit. It's gynormous

 

[pelipen]

Yes, that looks about right for a milk jug. I measured mine by weight since I figured my scale was more accurate than my measuring cups. Came out close enough as made no difference.

Plastic jugs sag also, which makes them appear to hold more than if you square up the sides. You'll see the level change the first time you open just about any beverage in a plastic container, so the discrepancy isn't as large as it appears.

 

[beertastic]

I used a 2 qt picture to measure out gallon marks on my keggle and a glass measuring cup to find out where the actual 2 qt mark came up to on that picture. (do you think you could shrink your image a bit. It's gynormous

OK, you were right. It was so big I couldn't find the edit button for a sec.

 

[brushvalleybrewer]

That looks about right from my experience. Glass one-gallon jugs, too.

 

[Stauffbier]

I came up with the same thing on my plastic jugs with a measuring cup. To think I used to just fill them up to the top thinking it was a gallon. I never could figure out why I always had more water than I was supposed to have.. When I started AG I figured it all out..

 

[cswest]

I use a 4 quart aluminum pitcher I got from Northern Brewer. It's cheap, marked off at each quart and works well with hot liquids. I highly recommend it.

 

[Stauffbier]

I use a 4 quart aluminum pitcher I got from Northern Brewer. It's cheap, marked off at each quart and works well with hot liquids. I highly recommend it.

I made a DIY mash paddle with with notches for my kettle.. I put notches for 1/4, 1/2, 3/4, and full gallon graduations up to 9 gallons. that works great for me now..

 

[RM-MN]

Producers of liquids must have at least the advertised amount in the jug and when filling they need a little extra space to make sure that the advertised amount will fit so the jugs must be larger than the anticipated fill amount. Your gallon jug looks fine.

 

[Paul07293]

your are always better going by weight to determine your volumes

1 gallon of water = 8.345 264 109 3 Pounds

metric is even easier

1 liter = 1 kilogram @4C

round off as is most convenient and you'll still be more accurate than using measuring cups

 

[Misplaced_Canuck]

I use a Cambro 4-quart pitcher. The 4-qt mark is dead-on, as verified by weight.

MC

 

[bctdi]

I use a graduated cylinder. It's a lot more narrow so it's more accurate than eyeballing something like a pitcher or anything with a wide footprint.Remember even if you're off a little bit on a quart by quart basis, by the time you get your starting water volume for a 5 gallon batch, it will be off by a significant amount ( enough to throw off your expected OG) . I would notch your mash paddle based on being super accurate with your water volume. Once you do that 1 time, it will be accurate from that point forward and your numbers will all make sense. If you do it wrong the first time, all of your batches going forward will be off, so it's worth the extra effort to be a little "anal" about it when you are setting up your baseline.

 

[malkore]

yep this is why i got a 4qt hard plastic measuring pitcher for food-service use. Its a little more accurate, doesn't sag, pours well, and has big permanent markings, for $5.

helpful to have a wife who works in a commercial kitchen and does the ordering. I've thought about having her get me a nice stockpot, but I still have a keggle-in-waiting to be cut and welded.

 

[Satisfaction]

your are always better going by weight to determine your volumes

1 gallon of water = 8.345 264 109 3 Pounds

metric is even easier

1 liter = 1 kilogram @4C

round off as is most convenient and you'll still be more accurate than using measuring cups

This is what I do, on brew days the bathroom scale is in the kitchen.

 

[Poobah58]

your are always better going by weight to determine your volumes

1 gallon of water = 8.345 264 109 3 Pounds

metric is even easier

1 liter = 1 kilogram @4C

round off as is most convenient and you'll still be more accurate than using measuring cups

That's just crazy. Water weight varies with temperature. Get a measuring cup!

 

[Satisfaction]

That's just crazy. Water weight varies with temperature. Get a measuring cup!

Well.. Same with volumes..

To expand, the difference in water weight at from 60F and 90F is around .03 lb/gallon. So fairly accurate

 

[HopSong]

Agee, seems a bit overkill. When you mark your jug do you fill to the top of the mark or the bottom of the mark? Those felt tip pens can be wide.

When you weigh the water, do you carry it out to 10 decimal places?

I've never been to a commercial brewery, but, I'll bet they don't fill up the kettles with extreme accuracy. After all is said and done, It's all good information, but brewing beer is not rocket science. Finding your own standard and modifying your recipe a bit at a time, I'd guess is the name of the game.

I'll bet the marks on the milk jug will work just fine. Fill up your brew kettle using the jug and then make marks on your spoon or paddle to simplify the next go round.

 

[Satisfaction]

When you weigh the water, do you carry it out to 10 decimal places?

Not something I do even at the lab at work with scales that measure down to 0,0005g. In the world of theoretical physics it would matter.

You hit the limits of measurability extremely fast with home equipment. I worry about the nearest 0,1lb. Though I do add corrections for water temperature as previously discussed. Here is a good calculator if you do not have a handy water density table at hand.

http://antoine.frostburg.edu/chem/senese/javascript/water-density.html

This is bringing back memories of one of my professors.. Always remember the significant digits.

 

[Esmitee]

I use a 4 quart aluminum pitcher I got from Northern Brewer. It's cheap, marked off at each quart and works well with hot liquids. I highly recommend it.

CSWEST, I just got the same pitcher from NB too. Used it once with, at the time, a little confusion.

What is a full gallon, all the way up to the brim, OR where the bend begins?

I guess I should use a measuring cup to find out for my own good!

 

[pelipen]

Well.. Same with volumes..

To expand, the difference in water weight at from 60F and 90F is around .03 lb/gallon. So fairly accurate

No no no. you are talking about density. Density = mass / volume.
the mass does not change unless it evaporates. This is a fundamental law.
Volumes can change as a function of temperature, therefore density changes as well. But it's insignificant compared to the expansion and contraction of your measuring container at various temps.
Always calibrate and measure at as close to the same temp as possible... But there is a realistic "do I really care" factor, in that if you are off by a couple cups nobody will notice.

 

[muthafuggle]

One thing no one here has mentioned yet... If you used a measuring cup meant for dry ingredients (avoirdupois), the volume is different than a liquid cup (1/16th of a gallon.)

In most kitchens, that's the difference between a metal or plastic measuring cup and the clear Pyrex measuring device with a lip on it.

The difference is not small.

 

[Paul07293]

When you weigh the water, do you carry it out to 10 decimal places?

Of course I don't weigh out to 10 decimal places, that's why I wrote you can round off to wherever you like. When I marked my brew kettle I only went out 2 decimal places. It's still more accurate than eyeballing the level on a pitcher or measuring cups.

In addition, when you use weight versus volume you don't have to worry about the inevitable question; where do I read the water level? At the top, middle or bottom of the meniscus.

 

[HopSong]

Actually, Paul, they were rhetorical questions.. not meant to be a dis.

 

[Paul07293]

Actually, Paul, they were rhetorical questions.. not meant to be a dis.

not taken as a dis, it's all good!

 

[zeg]

One thing no one here has mentioned yet... If you used a measuring cup meant for dry ingredients (avoirdupois), the volume is different than a liquid cup (1/16th of a gallon.)

I don't believe this is correct. Avoirdupois refers to the weight measurement system with a 16oz pound equal to about 454 g. There certainly is confusion between ounces avoirdupois (weight), Troy ounces (weight), and fluid ounces (volume), though.

A cup is the same, whether liquid or dry. The dry measuring cup differs from the wet in that it doesn't have any extra space to prevent spilling, but the volumes ought to be the same if both measuring cups are built to spec.

 

[HopSong]

http://www.infoplease.com/askeds/1-cup-=-1-cup.html

 

[1MadScientist]

Gosh, I thought one gallon of milk came up to the top. No wonder my beer is thin. Go and thin no more.

Seriously, I calibrated my keggle sight glass using a one gallon water jug thinking to the top was one gallon. Oh well, my beer still tastes good to me, no turning back...

 

[Sideways]

I second using a scale and weighing out the volumes. I batch sparge so its super easy to determine volumes if you already know the tare weight of your equipment. I tried measuring out volumes in a container when I started and it is time consuming. Using a scale is quick and way more precise. I saw much improvement in hitting my target numbers when I switched to this method.

 

[beertastic]

I second using a scale and weighing out the volumes. I batch sparge so its super easy to determine volumes if you already know the tare weight of your equipment. I tried measuring out volumes in a container when I started and it is time consuming. Using a scale is quick and way more precise. I saw much improvement in hitting my target numbers when I switched to this method.

Yeah but...how precise is your scale? It never ends.

The only scale I have that could weigh gallons of water would be my bathroom scale. I'm not sure I trust that more than eyeing it with a marked gallon jug. Plus how would I even fit my kettle on there?

 

[lou2row]

Yeah but...how precise is your scale? It never ends.

The only scale I have that could weigh gallons of water would be my bathroom scale. I'm not sure I trust that more than eyeing it with a marked gallon jug. Plus how would I even fit my kettle on there?

Right, I can't trust weighing my ingredients to my bathroom scale. According to that lying bastard, I'm morbidly obese!

 

[Sideways]

All great points... I use a $30 digital scale from Bed Bath and Beyond. I brought it to work and checked it with some calibrated weights and it was accurate within 0.5 lbs up to 100 lbs. If you are weighing out 5 gallons of water, that gives you about a 1% accuracy. I don't think I could measure out 5 gallons of water in a container and be accurate within 1%. I use a tripod carboy drainer placed upside down on the scale to elevate whatever it is I'm weighing so I can see the numbers.

As for the variation in volume at different temepratures, it doesn't matter. For me it makes sense that in batch sparging it's better to calculate strike temepratures by knowing the mass of additions, not the volume.